@rownum variable not working in lesson 14.5

[davidgilbertson]

Description

Page URL: https://docs.qgis.org/3.34/en/docs/training_manual/forestry/systematic_sampling.html

This page refers to a variable @rownum which doesn't exist in the current QGIS version. There's now a @row_number variable but that appears to not work (in the preview, it is always 1) and when I actually create the field, it doesn't populate at all.

[DelazJ]

@davidgilbertson Indeed, it should be @row_number (see #9113)
I tested the expression with another layer and it worked as expected. It however fails (I got Null values and not 'P_') when I also checked the "create virtual field" as you did in your screenshot. Mind unchecking that option, set appropriate field length and retry?

[davidgilbertson]

Yep, that works, thanks!